Bradbury foreshadows the fact that Lydia and George are going to be killed by the virtual reality lions several times throughout the story. The most overt example of foreshadowing comes as George and Lydia are discussing the way their children Wendy and Peter responded negatively to their parents shutting them out of their virtual reality nursery, as seen in the following passage:
A moment later they heard the screams.
Two screams. Two people screaming from downstairs. And then a roar of lions.
“Wendy and Peter aren’t in their rooms,” said his wife.
He lay in his bed with his beating heart. “No,” he said. “They’ve broken into the nursery.”
“Those screams—they sound familiar.”
“Do they?”
“Yes, awfully.”
Lydia and George hear two screams coming from the nursery, followed by a roar of lions, and realize that Wendy and Peter have broken into the room, despite being banned from entering it. The way that Lydia asserts that the screams “sound familiar” foreshadows the fact that the two of them will die at the hands of these lions. In fact, those screams are their screams, or at least the screams of their virtual reality counterparts, which the children created in order to practice their murderous scheme. This becomes clear when, after being locked in the room with the lions near the end of the story, the narrator notes, “And suddenly they realized why those other screams had sounded familiar.”
The parents’ fear of their children in this scene—the fact that they lay there with “beating hearts” instead of getting up to reprimand Wendy and Peter—demonstrates that they have lost all authority as the heads of the family. The Happylife Home, in effect, has destroyed the natural hierarchy—and close relationships—of the family unit.